Properties of the extended lobes of radio galaxies and quasars in the framework of the "flip-flop" model

The observed asymmetry of the radio images of double-lobed quasars in the 3 CR and 4C surveys is examined as a function of their radio luminosity. Theo retical models explaining various aspects of this asymmetry discussed earli er in the literature are considered. The observational data can be explaine d using a "flip-flop" model with certain relationships between temporal par ameters. In this case, the number of times the radio jet has changed direct ion increases from three for quasars with radio luminosities P > 10(28) W/H z to five for quasars with P < 10(28) W/Hz. Some peculiarities of the struc tures of radio sources are discussed in the framework of this flip-flop mod el.